Biggest Bang for your Buck ??

[GeorgeIoak]

I'm working on a project that is very cost sensitive but will require 1 white HBLED. It looks like Future carries a good selection of the Luxeon Rebel but I wanted to get some feedback if anyone had any other suggestions.

I built up 1 prototype using an OSRAM Golden Dragon that I had laying around (LW W5SG) and that had good output. I'm building a circuit based on the National LM3402MM so I'll have a constant current source of 350mA.

The project is for a retail display so the lifetime will short as those displays are usually throw away items after they get tired of them. I'll be building 500 or 1,000 units so I've got a little volume to help with the cost reduction. Color is not critical other than white but probably lean more towards a cool or neutral rather than warm.

Any input or pointers in the right direction to get cost vs. light output would be greatly appreciated.

Thanks,
George

 

[lolzertank]

I'm assuming you want a emitter in the 100 to 200 lumen range from your current choices. Lumens/$ would probably be either the Bridgelux or the SST-90, but those are probably much too bright. The Rebels are pretty cheap, and at your quantities, you could probably pick up 90 lumen @350ma Rebels for about $2 a piece.

 

[GeorgeIoak]

Sounds like you agree that the Rebels are probably a good fit when looking for something ~$2 mark?

From the datasheets it seems that the Rebels would be brighter than the Golden Dragon, would you agree?

 

[lolzertank]

The highest binned Golden Dragon Plus should at least match it, but as far as I know it's about 50% more expensive. That's on Mouser though, I don't know where you else you could get them. Cree XP-Es could be another choice, but they seem to run about $3-4 in quantities of 1000 on Arrow.

 

[GeorgeIoak]

It's looking more and more like the Rebels are the way to go.

I want to stay away from MCPCB for this project for cost concerns again and my board size will be rather large so I was trying to find some good information on how much copper area I would need to dedicate to the cooling of the Rebel assumming I'll use standard 1oz copper on my board.

Can you point me to any good spreadsheets or information on this?

 

[lolzertank]

I think there's information on Philips Lumileds' website. Since the Rebel's pad is electrically isolated, you could use lots of vias which should be pretty much free.